Tag: 200-300

Reaction Kinetics in Ionic Liquids as Studied by Pulse Radiolysis: Redox Reactions in the Solvents Methyltributylammonium Bis(trifluoromethylsulfonyl)imide and N-Butylpyridinium Tetrafluoroborate was written by Behar, D.;Neta, P.;Schultheisz, Carl. And the article was included in Journal of Physical Chemistry A in 2002.Recommanded Product: 1-Butyl-4-methylpyridin-1-ium bromide This article mentions the following:

Rate constants for several reduction and oxidation reactions were determined by pulse radiolysis in three ionic liquids and compared with rate constants in other solvents. Radiolysis of the ionic liquids methyltributylammonium bis(trifluoromethylsulfonyl)imide (R₄NNTf₂), N-butylpyridinium tetrafluoroborate (BuPyBF₄), and N-butyl-4-methylpyridinium hexafluorophosphate (BuPicPF₆) leads to formation of solvated electrons and organic radicals. In R₄NNTf₂ the solvated electrons do not react rapidly with the solvent and were reacted with several solutes, including CCl₄, benzophenone, and quinones. In the pyridinium ionic liquids the solvated electrons react with the pyridinium moiety to produce a pyridinyl radical, which, in turn, can transfer an electron to various acceptors. The rate constant for reduction of duroquinone by the benzophenone ketyl radical in R₄NNTf₂ (k = 2 × 10⁷ L mol^-1 s^-1) is much lower than that measured in water (k = 2 × 10⁹ L mol^-1 s^-1) due to the high viscosity of the ionic liquid Rate constants for electron transfer from the solvent-derived butylpyridinyl radicals in BuPyBF₄ and BuPicPF₆ to several compounds (k of the order of 10⁸ L mol^-1 s^-1) also are lower than those measured in water and in 2-PrOH, but are significantly higher than the diffusion-controlled rate constants estimated from the viscosity, suggesting an electron hopping mechanism through solvent cations. Electron transfer between Me viologen and quinones takes place 3 or 4 orders of magnitude more slowly in BuPyBF₄ than in water or 2-PrOH and the direction of the electron transfer is solvent dependent. The driving force reverses direction on going from water to 2-PrOH and is intermediate in the ionic liquid Radiolysis of ionic liquid solutions containing CCl₄ and O₂ leads to formation of CCl₃O₂^• radicals, which oxidize chlorpromazine (ClPz) with rate constants near 1 × 10⁷ L mol^-1 s^-1, i.e., much lower than in aqueous solutions and close to rate constants in alcs. On the other hand, the exptl. rate constants in the ionic liquids and in water are close to the resp. diffusion-controlled limits while the values in alcs. are much slower than diffusion-controlled. In the experiment, the researchers used many compounds, for example, 1-Butyl-4-methylpyridin-1-ium bromide (cas: 65350-59-6Recommanded Product: 1-Butyl-4-methylpyridin-1-ium bromide).

1-Butyl-4-methylpyridin-1-ium bromide (cas: 65350-59-6) belongs to pyridine derivatives. The ring atoms in the pyridine molecule are sp2-hybridized. The nitrogen is involved in the π-bonding aromatic system using its unhybridized p orbital. The lone pair is in an sp2 orbital, projecting outward from the ring in the same plane as the σ bonds. One of the examples of pyridines is the well-known alkaloid lithoprimidine, which is an A3 adenosine receptor antagonist and N,N-dimethylaminopyridine (DMAP) analog, commonly used in organic synthesis.Recommanded Product: 1-Butyl-4-methylpyridin-1-ium bromide

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Lanthanide complexes of polycarboxylate-bearing dipyrazolylpyridine ligands with near-unity luminescence quantum yields: the effect of pyridine substitution was written by Brunet, Ernesto;Juanes, Olga;Sedano, Rosa;Rodriguez-Ubis, Juan-Carlos. And the article was included in Photochemical & Photobiological Sciences in 2002.Product Details of 408352-58-9 This article mentions the following:

The title complexes displayed a marked dependence of their luminescence properties upon pyridine substitution. The ligand with the 4-carbamoyl-substituted pyridine showed a long-lived luminescence of near-unity quantum yield for Tb³⁺ and quite reasonable values for Eu³⁺, Sm³⁺ and Dy³⁺, thus making it an excellent candidate for a luminescent probe to be attached to biomols. by a peptide-like linkage. In the experiment, the researchers used many compounds, for example, 2,6-Dibromoisonicotinonitrile (cas: 408352-58-9Product Details of 408352-58-9).

2,6-Dibromoisonicotinonitrile (cas: 408352-58-9) belongs to pyridine derivatives. Pyridine’s the lone pair does not contribute to the aromatic system but importantly influences the chemical properties of pyridine, as it easily supports bond formation via an electrophilic attack. Several pyridine derivatives play important roles in biological systems. While its biosynthesis is not fully understood, nicotinic acid (vitamin B3) occurs in some bacteria, fungi, and mammals.Product Details of 408352-58-9

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Supramolecular Coordination Complexes with 5-Sulfoisophthalic Acid and 2,5-Bipyridyl-1,3,4-Oxadiazole: Specific Sensitivity to Acidity for Cd(II) Species was written by Li, Cheng-Peng;Yu, Qian;Chen, Jing;Du, Miao. And the article was included in Crystal Growth & Design in 2010.Electric Literature of C12H8N4O This article mentions the following:

Cd^II, Co^II, Ni^II, and Pb^II mixed-ligand coordination complexes based on 5-sulfoisophthalic acid (H₃sip) and the bent dipyridyl ligand 2,5-bis(3-pyridyl)-1,3,4-oxadiazole (3-bpo) or its 4-pyridyl N-donor analog (4-bpo) were synthesized and fully characterized by IR spectra, microanalyses, and single crystal and powder x-ray diffraction techniques. The significant pH effect on assembly of the Cd^II complexes was demonstrated, which gives distinct crystalline products, whereas the Co^II, Ni^II, and Pb^II systems are independent to pH condition of the synthetic reaction. The eight prepared complexes display various coordination motifs with different existing forms, conformations, and coordination modes of the organic ligands. Further, extended supramol. networks are constructed via secondary interactions such as H-bonding and aromatic stacking. Solid-state properties of thermal stability and fluorescence for these crystalline materials are also presented. In the experiment, the researchers used many compounds, for example, 2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole (cas: 15420-02-7Electric Literature of C12H8N4O).

2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole (cas: 15420-02-7) belongs to pyridine derivatives. Pyridine’s the lone pair does not contribute to the aromatic system but importantly influences the chemical properties of pyridine, as it easily supports bond formation via an electrophilic attack. Pyridine, its benzo and pyridine-based compounds play diverse roles in organic chemistry. Pyridine-based materials are valued for their optical and physical properties as well as their medical potential. Electric Literature of C12H8N4O

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Synthesis, SAR study, and biological evaluation of a series of piperazine ureas as fatty acid amide hydrolase (FAAH) inhibitors was written by Kono, Mitsunori;Matsumoto, Takahiro;Kawamura, Toru;Nishimura, Atsushi;Kiyota, Yoshihiro;Oki, Hideyuki;Miyazaki, Junichi;Igaki, Shigeru;Behnke, Craig A.;Shimojo, Masato;Kori, Masakuni. And the article was included in Bioorganic & Medicinal Chemistry in 2013.Synthetic Route of C11H20N2O2S This article mentions the following:

A series of piperazine ureas was designed, synthesized, and evaluated for their potential as novel orally available fatty acid amide hydrolase (FAAH) inhibitors that are therapeutically effective against pain. We carried out an optimization study of the lead compound to improve its DMPK profile as well as in vitro potency. We identified the thiazole compound I with potent inhibitory activity, high brain permeability, and good bioavailability. Compound I showed a potent and dose-dependent anti-nociceptive effect in the acetic acid-induced writhing test in mice. In the experiment, the researchers used many compounds, for example, tert-Butyl 4-carbamothioylpiperidine-1-carboxylate (cas: 214834-18-1Synthetic Route of C11H20N2O2S).

tert-Butyl 4-carbamothioylpiperidine-1-carboxylate (cas: 214834-18-1) belongs to pyridine derivatives. Pyridine’s the lone pair does not contribute to the aromatic system but importantly influences the chemical properties of pyridine, as it easily supports bond formation via an electrophilic attack. One of the examples of pyridines is the well-known alkaloid lithoprimidine, which is an A3 adenosine receptor antagonist and N,N-dimethylaminopyridine (DMAP) analog, commonly used in organic synthesis.Synthetic Route of C11H20N2O2S

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Safety Evaluation of the Copper-Mediated Cross-Coupling of 2-Bromopyridines with Ethyl Bromodifluoroacetate was written by Yang, Qiang;Cabrera, Pablo J.;Li, Xiaoyong;Sheng, Min;Wang, Nick X.. And the article was included in Organic Process Research & Development in 2018.COA of Formula: C6H3BrF3N This article mentions the following:

Potential safety hazards associated with Cu-mediated cross-coupling of 2-bromopyridines with Et bromodifluoroacetate were evaluated. An accelerating rate calorimetry thermal stability evaluation of the post-reaction mixture of 50.6 mmol 2-bromopyridine with 1.3 equivalent Et bromodifluoroacetate in the presence of 2.1 equivalent Cu in 40 mL DMSO indicated a significant decomposition event with a 115.5° onset temperature, which was significantly lower than that of neat DMSO. The reaction mixture in N,N-dimethylformamide did not display any exothermic decomposition up to 400° using differential scanning calorimetry. Reaction calorimetry evaluation of this reaction in DMSO showed a heat output (ΔH) of -13.5 kJ and an adiabatic temperature rise (ΔT_ad) of 129.5°, resulting in a maximum temperature of a synthesis reaction (MTSR) of 189.5°. The predicted heat of reaction using d. functional theory with BLYP functional agreed well with exptl. data. Scope studies with a multiple substituted 2-bromopyridines showed similar ΔH and ΔT_ad magnitudes vs. 2-bromopyridine when reacted at the same concentration In all studied cases, MTSR was significantly higher than the onset temperature of reaction mixture decomposition, indicating that in the absence of active cooling, the system could quickly trigger decomposition of the reaction mixture and result in a runaway reaction. In the experiment, the researchers used many compounds, for example, 2-Bromo-3-(trifluoromethyl)pyridine (cas: 175205-82-0COA of Formula: C6H3BrF3N).

2-Bromo-3-(trifluoromethyl)pyridine (cas: 175205-82-0) belongs to pyridine derivatives. Pyridine’s the lone pair does not contribute to the aromatic system but importantly influences the chemical properties of pyridine, as it easily supports bond formation via an electrophilic attack. Reduced pyridines, namely tetrahydropyridines, dihydropyridines and piperidines, are found in numerous natural and synthetic compounds. The synthesis and reactivity of these compounds have often been driven by the fact many of these compounds have interesting and unique pharmacological properties. COA of Formula: C6H3BrF3N

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Advancing the Mechanistic Understanding of an Enantioselective Palladium-Catalyzed Alkene Difunctionalization Reaction was written by Jensen, Katrina H.;Webb, Jonathan D.;Sigman, Matthew S.. And the article was included in Journal of the American Chemical Society in 2010.Computed Properties of C13H15F3N2O This article mentions the following:

The mechanism of an enantioselective palladium-catalyzed alkene difunctionalization reaction has been investigated. Kinetic anal. provides evidence of turnover-limiting attack of a proposed quinone methide intermediate with MeOH and suggests that copper is involved in productive product formation, not just catalyst turnover. Through examination of substrate electronic effects, a Jaffe relationship was observed correlating rate to electronic perturbation at two positions of the substrate. Ligand effects were evaluated to provide evidence of rapid ligand exchange between palladium and copper as well as a correlation between ligand electronic nature and enantioselectivity. In the experiment, the researchers used many compounds, for example, (S)-4-(tert-Butyl)-2-(4-(trifluoromethyl)pyridin-2-yl)-4,5-dihydrooxazole (cas: 1257527-14-2Computed Properties of C13H15F3N2O).

(S)-4-(tert-Butyl)-2-(4-(trifluoromethyl)pyridin-2-yl)-4,5-dihydrooxazole (cas: 1257527-14-2) belongs to pyridine derivatives. Pyridine has a conjugated system of six π electrons that are delocalized over the ring. The molecule is planar and, thus, follows the Hückel criteria for aromatic systems. Reduced pyridines, namely tetrahydropyridines, dihydropyridines and piperidines, are found in numerous natural and synthetic compounds. The synthesis and reactivity of these compounds have often been driven by the fact many of these compounds have interesting and unique pharmacological properties. Computed Properties of C13H15F3N2O

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

A new method of synthesis of 1,3,4-oxadiazoles from aromatic acids and semicarbazide with polyphosphoric acid was written by Ren, Zhong-Jiao;Jiang, E.;Zhou, Hong-Bin. And the article was included in Youji Huaxue in 1995.Application of 15420-02-7 This article mentions the following:

Oxadiazoles I (R = Ph, substituted Ph, 3-pyridyl, 4-pyridyl) were prepared in 41-95% yield by stirring RCO₂H with semicarbazide hydrochloride and polyphosphoric acid at 150-160° for 1 h. In the experiment, the researchers used many compounds, for example, 2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole (cas: 15420-02-7Application of 15420-02-7).

2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole (cas: 15420-02-7) belongs to pyridine derivatives. Pyridine is diamagnetic and has a diamagnetic susceptibility of −48.7 × 10−6 cm3·mol−1.The molecular electric dipole moment is 2.2 debyes. The standard enthalpy of formation is 100.2 kJ·mol−1 in the liquid phase and 140.4 kJ·mol−1 in the gas phase. Halopyridines are particularly attractive synthetic building blocks in a variety of cross-coupling methods, including the Suzuki-Miyaura cross-coupling reaction.Application of 15420-02-7

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Subtype-selective Na_v1.8 sodium channel blockers: Identification of potent, orally active nicotinamide derivatives was written by Kort, Michael E.;Atkinson, Robert N.;Thomas, James B.;Drizin, Irene;Johnson, Matthew S.;Secrest, Matthew A.;Gregg, Robert J.;Scanio, Marc J. C.;Shi, Lei;Hakeem, Ahmed H.;Matulenko, Mark A.;Chapman, Mark L.;Krambis, Michael J.;Liu, Dong;Shieh, Char-Chang;Zhang, XuFeng;Simler, Gricelda;Mikusa, Joseph P.;Zhong, Chengmin;Joshi, Shailen;Honore, Prisca;Roeloffs, Rosemarie;Werness, Stephen;Antonio, Brett;Marsh, Kennan C.;Faltynek, Connie R.;Krafte, Douglas S.;Jarvis, Michael F.;Marron, Brian E.. And the article was included in Bioorganic & Medicinal Chemistry Letters in 2010.Electric Literature of C8H8BrNO2 This article mentions the following:

A series of aryl-substituted nicotinamide derivatives with selective inhibitory activity against the Na_v1.8 sodium channel is reported. Replacement of the furan nucleus and homologation of the anilide linker in subtype-selective blocker A-803467 (1) provided potent, selective derivatives with improved aqueous solubility and oral bioavailability. Representative compounds from this series displayed efficacy in rat models of inflammatory and neuropathic pain. In the experiment, the researchers used many compounds, for example, Ethyl 2-bromoisonicotinate (cas: 89978-52-9Electric Literature of C8H8BrNO2).

Ethyl 2-bromoisonicotinate (cas: 89978-52-9) belongs to pyridine derivatives. Pyridines are an important class of heterocycles and occur in polysubstituted forms in many naturally occurring biologically active compounds, drug molecules and chiral ligands. Pyridine, its benzo and pyridine-based compounds play diverse roles in organic chemistry. Pyridine-based materials are valued for their optical and physical properties as well as their medical potential. Electric Literature of C8H8BrNO2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Hysteretic four-step spin-crossover in a 3D Hofmann-type metal-organic framework with aromatic guest was written by Zhang, Cui-Juan;Lian, Kai-Ting;Huang, Guo-Zhang;Bala, Sukhen;Ni, Zhao-Ping;Tong, Ming-Liang. And the article was included in Chemical Communications (Cambridge, United Kingdom) in 2019.Recommanded Product: 15420-02-7 This article mentions the following:

A new Hofmann-type metal-organic framework with bent pillar ligand, [Fe(dpoda){Ag(CN)₂}₂] (dpoda = 2,5-di-(pyridyl)-1,3,4-oxadiazole), was synthesized. Four-, two- and one-step spin-crossover (SCO) properties were obtained by using different sizes of aromatic guests. Most importantly, hysteretic four-step SCO behavior with the sequence of LS ↔ HS_0.25LS_0.75 ↔ HS_0.5LS_0.5 ↔ HS_0.67LS_0.33 ↔ HS is observed for the first time. In the experiment, the researchers used many compounds, for example, 2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole (cas: 15420-02-7Recommanded Product: 15420-02-7).

2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole (cas: 15420-02-7) belongs to pyridine derivatives. The pyridine ring occurs in many important compounds, including agrochemicals, pharmaceuticals, and vitamins. Several pyridine derivatives play important roles in biological systems. While its biosynthesis is not fully understood, nicotinic acid (vitamin B3) occurs in some bacteria, fungi, and mammals.Recommanded Product: 15420-02-7

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Novel Cu^II, Co^II and Pb^II supramolecular networks of pyridine-2,6-dicarboxylate (pydc) in cooperation with a bent dipyridyl spacer via coordinative, hydrogen-bonding and aromatic stacking interactions was written by Du, Miao;Cai, Hua;Zhao, Xiao-Jun. And the article was included in Inorganica Chimica Acta in 2006.HPLC of Formula: 15420-02-7 This article mentions the following:

Reaction of M(OAc)₂ (M^II = Cu^II for 1, Co^II for 2, and Pb^II for 3) with pyridine-2,6-dicarboxylic acid (H₂pydc) in presence of a dipyridyl spacer, 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (bpo), affords three novel metal-organic supramol. networks, [Cu₂(bpo)(pydc)₂(H₂O)₃]·2.75H₂O (1), [Co(bpo)(pydc)(H₂O)₂]·(H₂O) (2) and [Pb(pydc)]_n (3), which were structurally determined by single-crystal x-ray diffraction. The dimeric Cu-pydc coordination framework bridged by a bpo spacer in 1 is hydrogen-bonded to four others to result in a two-dimensional (2-D) sheet array. The neutral monomeric mols. in 2 have an ordered 3-dimensional stacking stabilized via hydrogen bonds and significant π-π interactions in the lattice, possessing large porous channels with the inclusion of guest solvates. In coordination polymer 3, the Pb^II ion takes the unusual distorted capped trigonal prismatic geometry (PbNO₆) and each pydc dianion binds to four Pb^II centers to form a 2-dimensional infinite network. The thermal stabilities of these complexes also were studied. In the experiment, the researchers used many compounds, for example, 2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole (cas: 15420-02-7HPLC of Formula: 15420-02-7).

2,5-Di(pyridin-4-yl)-1,3,4-oxadiazole (cas: 15420-02-7) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ·mol−1 in pyridine vs. 150 kJ·mol−1 in benzene). Several pyridine derivatives play important roles in biological systems. While its biosynthesis is not fully understood, nicotinic acid (vitamin B3) occurs in some bacteria, fungi, and mammals.HPLC of Formula: 15420-02-7

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem